The goal of this program project is to understand the relationship between persistence of neurotropic virus and the development of acute and chronic neurologic disease. The program contains 3 scientific projects, an administrative core and a scientific core. Because oligoclonal bands (OGB) in multiple CNS infectious diseases are specific for the agent that causes disease, Project 1 analyzes B cell responses in MS brain and CSF. Although the specificity of OGB in MS is unknown, in the past funding period, we demonstrated a restricted and somatically mutated IgG repertoire indicative of an antigen-driven B cell response. Coexpression of over-represented VH and VL sequences in expression vectors identified 2 recombinant antibodies (Abs) specific for dsDNA. To improve the quality and production of recombinant Abs, we developed an efficient RT-PCR protocol that amplifies expressed VH and VL sequences in single B cells of MS CSF to produce recombinant Abs. Since our overall aim is to identify the antigen in MS against which the oligoclonal IgG is directed, we will clone and characterize cDNAs from MS CSF and brain whose protein products react with these antibodies, and analyze changes in the MS IgG repertoire with disease progression. The second and third projects center on 2 highly neurotropic herpes viruses: varicella zoster virus (VZV) and the closely related simian varicella virus (SVV), which displays clinical, pathological and virological features virtually identical to VZV in humans and allows studies not possible in humans. In the past funding period, Project 2 developed varicella latency in primates and will now identify cells in Intently infected monkey ganglia that harbor SW as well as all SW genes transcribed and translated during latency. Based on clinical protocols that reactivate human VZV, we will analyze SVV reactivation induced by x-irradiation, and by immunosuppressive and anti-inflammatory drug therapy. Project 3 will characterize VZV gene expression in Intently infected human ganglia by high-throughput transcriptional arrays and in situ immunohistochemistry, and will also determine the function of IE-63, the most prevalent and abundant VZV gene expressed during latency. A comprehensive knowledge of the physical state of latent and reactivated VZV and SVV will lead to experiments designed to prevent the cascade of events leading to human varicella reactivation, a cause of serious neurologic disease, particularly in the rapidly increasing elderly and immunocompromised populations. This proposal melds the skills and strategies of investigators with expertise in neurology, virology, molecular genetics and clinical investigation. This concerted effort is focused on prospective studies to delineate the cause, pathogenesis and eventual prevention of viral and demyelinating diseases of the human nervous system.